Treprostinil, the active ingredient in Remodulin®, Tyvaso® and Orenitram™, was first described in U.S. Pat. No. 4,306,075. Treprostinil, and other prostacyclin derivatives may be prepared as described in Moriarty, et al in J. Org. Chem. 2004, 69, 1890-1902, Drug of the Future, 2001, 26(4), 364-374, U.S. Pat. Nos. 6,441,245, 6,528,688, 6,700,025, 6,809,223, 6,756,117; 8,461,393; 8,481,782; 8,242,305; 8,497,393; US patent applications nos. 2012-0190888 and 2012-0197041; PCT publication no. WO2012/009816.
Various uses and/or various forms of treprostinil are disclosed, for examples, in U.S. Pat. Nos. 5,153,222; 5,234,953; 6,521,212; 6,756,033; 6,803,386; 7,199,157; 6,054,486; 7,417,070; 7,384,978; 7,879,909; 8,563,614; 8,252,839; 8,536,363; 8,410,169; 8,232,316; 8,609,728; 8,350,079; 8,349,892; 7,999,007; 8,658,694; 8,653,137; US patent application publications nos. 2005/0165111; 2009/0036465; 2008/0200449; 2010-0076083; 2012-0216801; 2008/0280986; 2009-0124697; 2013-0261187; PCT publication no. WO00/57701; U.S. provisional applications No. 61/781,303 filed Mar. 14, 2013 and 61/805,048 filed Mar. 25, 2013. The teachings of the aforementioned references are incorporated by reference to show how to practice the embodiments of the present invention.
The teachings of the aforementioned references are incorporated by reference to show how to practice the embodiments of the present invention. The methods described in these documents, however, do not describe a feasible production method for producing salts of treprostinil because the methods require the use of excessive amounts of reagents and tedious chromatographic purification techniques. Therefore, there is a need for an economical, efficient and simplified method for preparing salts of treprostinil.
In sum, treprostinil is of great importance from a medicinal point of view. Therefore, a need exists for stable forms of treprostinil which presents advantage in storage, shipment, handling, and/or formulation, for example. From synthetic point of view, the desired properties of UT-15 salts may include one or more of the following properties: better aqueous solubility, higher melting point, dense nature, and robust process.